Sump pump control system

ABSTRACT

A sump pump control system for monitoring and driving AC pumps that are supplied by directly either by AC utility power, or converted DC battery power. AC power is continuously monitored and the control automatically switches to DC battery supply in the case of power failure. DC battery power is converted to AC power. The control is equipped with unique pump switching circuitry allowing the pumps to be configured in parallel or staggered positions. Both pumps automatically alternate to prevent damage to pumps from humidity and corrosion that can result from remaining idle. Each pump has its own float switch to control operation. A third float switch controls both pumps in case of failure of either pump or float switch. Multiple visual and audio signals are included, displaying present power and pump conditions as well as alerting to any pump malfunction. The control utilizes two 12 volt deep cycle lead acid batteries that are being monitored for voltage level and continuously trickle charged to maintain maximum capacity. Batteries can be paralleled to obtain longer pump running time when AC power fails. The control system also allows for use of a single pump in the absence of a second pump.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of PPA Ser. No. 60/779,333, filedMar. 3, 2006 by the present inventor(s).

FEDERALLY SPONSORED RESEARCH

Not applicable

SEQUENCE LISTING OF PROGRAM

Not applicable

BACKGROUND OF INVENTION

1. Field of Invention

This invention generally relates to a pump control system, specificallya sump pump control unit which controls a plurality of alternating ACsump pumps operated by either AC power or inverted battery DC power.

2. Prior Art—Objects and Disadvantages

This invention monitors power and pump conditions, automaticallytriggering controlled alerts and responses. Both power and mechanicalpump status are continuously visually displayed. Pump mechanicalmalfunctions are visually displayed and alerted audibly.

Previously, control systems do not allow for a plurality of pumps tooperate from the same power sources. In these systems, the primary andbackup pumps are driven by different power sources.

U.S. Pat. No. 4,222,711 (Mayer) shows a system utilizing AC power for aprimary AC pump and a secondary DC pump powered by battery DC power. Inthis scenario, not only would the backup sump pump be a DC pump which isin general less powerful than an AC pump, but each pump is dependentupon one particular power source.

U.S. Pat. No. 6,676,382 (Leighton) shows a system utilizing one DC pump.The DC pump in general provides less gallons per minute pumping capacitythan an AC pump. The system does not allow for configuration and controlof more than one pump.

U.S. Pat. No. 5,234,319 converts AC to DC power to operate an AC motorwhich is then connected to a pumping device. The system does not allowfor the use of submersible AC sump pump or backup pump. In the case of afailed pump or motor, replacement would be dependent upon theavailability of motors and pumps that may not be readily available.

The unit in our application operates all pumps from the same powersources. Any pump will operate from AC power source when available andswitch to DC power source when AC power source fails. The advantage isthat in the case of a pump failure, operation of alternative pump wouldnot be limited to a single power source. AC Pumps as utilized in thisapplication provide higher overhead pressure and more gallons per minutepumping capacity than the DC auxiliary pumps used previously.

Sump pumps are activated when a float switch is triggered. Prior controlsystems have utilized one float switch to activate operation. The systemherein applied for utilizes an additional float switch, at a level abovethe other float switches, that serves as a backup in case of primaryfailures.

Additionally, sump pumps that remain idle can be subject to damage fromhumidity, corrosion, or blockage. The system alternates pump operationto protect from such damage and provide early alerts if problems exist.

The control unit further accommodates the positioning of pumps to beeither staggered or parallel. The unit alternates usage of pumps basedon this configuration. In the absence of a backup pump, the control unitallows for operation of a single pump.

Further objects and advantages of our invention will become apparentfrom a consideration of the drawings and ensuing description.

SUMMARY OF INVENTION

The invention consists of a pump control unit which is supplied witheither utility AC power, or inverted battery DC power in case of ACpower loss. The DC power is supplied by a plurality of sealed lead acidbatteries.

The pump control unit has several visual and audio indicators for normaland abnormal pump operation. These indicators include: AC power lights,DC power lights, primary mode lights and secondary mode lights. Audioalarm and visual indication for: overload for each pump, pump controlunit overheat, low battery A, low battery B, check primary pump, checksecondary pump, and the battery charging status. Total battery voltageis displayed with digital voltmeter. Battery charging circuit andinverter overload protection are included.

Two pumps may be positioned in parallel or may be staggered. The controlwill function with a single pump in the absence of a secondary pump.Pump switching circuitry monitors pumps for malfunctions and switchesoperation accordingly, as well as alternating pump usage under normalconditions to protect against damage than can be caused by an extendedidle state.

Three float switches provide a high level of security.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 shows the sump pump control system with a single pumpconfiguration

FIG. 2 shows the sump pump control system with a double pump in parallelconfiguration

FIG. 3 shows the sump pump control system with a double pump instaggered configuration

FIG. 4 shows the main power supply for switching logic, and sensing anddriving circuits

FIG. 5 shows the power distribution to the pumps

FIG. 6 shows the DC to DC conversion in two stages—part one of two

FIG. 7 shows the DC to AC conversion in two stages—part two of two

FIG. 8 is a flowchart representing the logic of pump operation inparallel configuration

FIG. 9 is a flowchart representing the logic of pump operation instaggered configuration (1 of 2)

FIG. 10 is a flowchart continuing the logic of pump operation instaggered configuration (2 of 2)

FIG. 11 is a flowchart representing the logic of pump operation insingle configuration

DETAILED DESCRIPTION OF INVENTION Operation of System:

The pump operation is established with one pump as a backup pump and apair of lead acid batteries as a backup power supply. The pump controlunit serves as replacement for the utility power, in the case of ACpower loss and is active for battery power as well. The control unitserves also as an alternative energy device that replaces gas-fueledgenerators. It is equipped with advanced pump switching logic toaccommodate for normal and abnormal pump operation. The pump switchingand pump control logic is active for battery power as well as AC powermode.

The pump control unit operates in 3 modes; the user has the option tochoose between the 3 modes:

-   -   1. Single pump configuration (utilizes 100% of the pump        operation) (FIG. 1)    -   2. Double pump in parallel configuration (utilizes 50% duty of        each pump) (FIG. 2)    -   3. Double pump in staggered configuration (utilizes 80% duty of        primary and 20% duty of secondary pump). (FIG. 3)

Each pump has a pressure switch that activates either the correspondingor alternate pump, depending on selected application. An additionalsecurity switch is also mounted at the maximum allowable water level. Inno instance will both pumps cycle simultaneously.

Once the pump control and pumps are configured by a professional, itdoes not require human interaction since the processes are conductedautomatically. The batteries recharge automatically and are maintainedat the maximum capacity level. Pumps will be automatically monitored forelectrical and mechanical malfunction.

The user task consists of monitoring the unit for abnormal operation asindicated by audio and visual alarms.

The control operates in one of 3 ways depending on the pumpconfiguration:

Operation of the Single Pump Configuration: (FIG. 1)

When the pump pressure switch closes, the pump starts cycling. When thepump pressure switch opens the pump turns off. Under normal conditionthis cycle continues as described above. If the pump is cycling and thewater reaches the maximum level switch, the operation continues followedby a visual and audio alarm.

A special case, defined as the state of overload, is induced when thepump is clogged due to the presence of a substance that cannot beevacuated. The pump draws more power and it can be damaged if itcontinues to run. Overload condition may also be induced by a short inthe pump itself or shorted pump cable. When the pump overload is sensed,the pump shuts down followed by the visual and audio alarm. Thiscondition is maintained until the “overload reset” button is pressed(this should be done by a professional since the pump exerted abnormaloperation).

Operation of the Double Pump in Parallel Configuration: (FIG. 2)

In parallel configuration pump 1 and pump 2, as well as their pressureswitches, should be installed at the same level in the sump hole.

Normal operation commences as follows:

If the circuit is in the initial state, the pump control unit waits forthe primary pressure switch to close. The unit will automaticallydetermine (due to the minute differences in pressure switch level) whichpressure switch will be the primary and which will be the secondary.Both pressure switches should be installed on approximately the samelevel plane. When the primary pressure switch closes, pump 1 startscycling first (pump 2 remains inactive at this stage). After the primarypressure switch opens, pump 1 turns off and switches to pump 2 (pump 1remains inactive at this stage and pump 2 is in the cycle ready state).When the primary pressure switch closes again, pump 2 begins cycling.When primary pressure switch opens again, pump 2 turns off and switchesback to pump 1 (cycle ready state). Concerning primary and secondarypressure switch, each switch acts as a backup for the other one. Bothpressure switches are connected in parallel and will turn on either ofthe pumps when one of them is closed and turn off that pump only whenboth of them are open. Under normal conditions, this cycle continues asdescribed above and ensures equal number of cycles for each pump.

Fail Conditions Due to High Water Level:

If either of the pumps is cycling and the water reaches the maximumlevel switch, the operation will be turned over to the pump which wasnot cycling at that time followed by permanent visual and resettableaudio alarm. This condition remains until the “main reset” button,accessible only to plumbers, is pressed.

This operation prevents over flooding due to pump malfunction.

If the primary pump was cycling and the maximum level switch is reached,the pump control unit permanently assigns the operation to the secondarypump which will evacuate the water to the primary pressure switch level.Visual and audio alarms will be activated. If during next secondary pumpcycle the maximum level pressure switch is closed again, the secondarypump will continue to run followed by visual and audio alarm.

If the secondary pump was cycling and the maximum level switch isreached, the pump control unit permanently assigns the operation to theprimary pump which will evacuate the water to the primary pressureswitch level. Visual and audio alarms will be activated. If during nextprimary pump cycle, the maximum level pressure switch is closed again,the primary pump will continue to run followed by visual and audioalarm.

Overload:

In the case of overload, the operation is permanently assigned to thepump, which was NOT cycling at that time, followed by permanent visualand resettable audio alarm. This condition leaves the defective pumpinactive and the maximum level switch loses its functionality exceptalarm and visual indication. This condition remains until the “mainreset” button is pressed (accessible only to plumbers).

If the overload condition arises on the alternate pump also, both pumpsbecome inactive and remain inactive until the “main reset” button ispressed which will force the unit to its initial state.

Bad Switches:

In order for either pump to run one switch has to be closed, and foreither pump to turn off, both switches have to be open. If only primarypressure switch is bad, secondary pressure switch will take over thefunction. If only secondary pressure switch is bad, primary pressureswitch will take over its function. If both pump pressure switches arebad, no pump cycling will occur even when maximum level pressure switchcloses. Both check primary and check secondary pump flashing lights willbe on, followed by the audio alarm. If only maximum level pressureswitch is bad, no pump circuit switching will occur, the correspondingpump will continue cycling, and the visual and audio alarms will NOT beactivated.

Steps of Operation of the Double Pump in Staggered Configuration: (FIG.3)

In the staggered pump configuration primary pump and the correspondingpressure switch is the circuit which is installed at the ground level inthe sump hole. The secondary pump and corresponding pressure switch isthe circuit which is installed above the primary circuit.

Normal Operation:

When the pressure switch of the primary pump circuit is closed, primarypump starts cycling. After its switch opens the primary pump turns off.This operation will repeat four times and after the 4^(th) cycle, theprimary pump will be temporarily disabled and it will allow the water toreach the secondary pump which will cycle only once as long as itspressure switch is closed. After the water is evacuated below the levelof the secondary pump circuit pressure switch, the pump control unitreturns the operation to the primary pump circuit which will continue toremove the remaining water in the sump hole as long as its pressureswitch is closed. When the primary pump circuit pressure switch opens,the unit returns to the initial state and the cycle repeats. Undernormal conditions this operation ensures the secondary pump check valveclearance and 20% of total cycle counts.

Fail Conditions Due to High Water Level:

If the primary pump is cycling and the water level reaches the secondarypump pressure switch, the pump control unit will automatically switch tosecondary pump circuit, permanently disable primary pump circuit, andindicate permanent visual and resettable audio alarm. When the secondarypump pressure switch opens the secondary pump turns off and waits fornext cycle. This operation prevents over flooding due to primary pumpcircuit malfunction. If during next secondary pump circuit cycle themaximum level pressure switch is closed, the pump will continue to runfollowed by visual and audio alarm.

If the primary pump was cycling and the maximum level switch is reached,the primary pump will continue to run followed by permanent visual andresettable audio alarm (check pump 1 and pump 2 lights will be on). Thesecondary pump circuit is disabled due to bad pressure switch.

If the secondary pump was cycling and the maximum level switch isreached, the unit permanently assigns the operation to the primary pumpcircuit which will evacuate the water to its pressure switch level(ground level) followed by permanent visual and resettable audio alarm.If during next cycle the maximum level pressure switch is closed again,the primary pump will continue to run followed by permanent visual andresettable audio alarm. The warning lights will be lit until “mainreset” button is pressed.

Overload:

In the overload case, the operation is assigned to the pump which wasNOT cycling at that time and remains assigned to that pump. Thiscondition leaves defective pump circuit inactive and the maximum levelswitch loses its functionality except visual and audio alarm. Thiscondition remains until the “main reset” button is pressed.

If the overload condition arises on the alternate pump also, both pumpsbecome inactive and remain inactive until the “main reset” button ispressed which will force the unit to its initial state.

When the water reaches either the secondary pump pressure switch (unlessin 20% usage mode), or maximum level switch, or when the unit exerts theoverload, there will be an audio alarm followed by visual warningindicating which pump is malfunctioning.

DETAILED DESCRIPTION OF INVENTION—CONTINUED

The following invention includes but it is not limited to followingfeatures:

Highly efficient DC to AC conversion, transformer less inverter, pumpmotor soft start, battery bulk charger with trickle charger, 115Vrms/60Hz sine wave power signal for quieter and cooler pump operation, pumpoverload protection, backup pump provided with nominal power, 2 cascaded12V batteries to increase efficiency and prolong the running time,inverter short circuit protection, multiple LED to display the batteryand pump status, piezo sound alert, digital volt meter to displaypresent battery voltage, 3 float switches with the third float switchfor pump and float switch failure security, 3 operating modes such assingle pump, double pump in parallel and double pump in staggeredconfiguration.

FIG. 4

Main low voltage power supply for switching logic and driving andsensing circuits is delivered from Transformer T1 at 11 which steps down120Vac to 14Vac. This voltage is further rectified through Diodes D4 andD5 at 12, and filtered by capacitor C6 at 13. This power is delivered to12V regulator 28 at 13. From the other side unregulated 24 volts batteryvoltage at 14 is delivered to 29 voltage regulator through diode D3 at15. The 29 regulator is controlled by transistor Q1 at 16 which turnsthe regulator ON and OFF, depending on the status of AC power supply at17. If AC power is interrupted the transistor is turned OFF through R4at 18 and the 29 regulator is providing the voltage at the output 19 tosupply the 12V regulator through diode D1 at 13.

This method allows generation of an uninterrupted +12V supply at 25which is distributed through analog and digital active and passive lowpower components. Also the AC power detector logic and relay drivercircuit is using voltage at 17 to obtain the signal at 26 to drive relayRL3 which routes AC or inverted DC battery power to pump relays. Batteryvoltage is constantly monitored at 20 and 21 and visually displayed onthe front panel by a digital volt meter at 14. Low battery voltages willbe indicated by visual and audio alarm.

The Sinusoidal Pulse Width Modulation or abbreviated SPWM is generatedby SPWM circuitry at 27 which is triggered by crystal oscillator at 22.

Obtained SPWM signals are split into two halves marked as SPWM A at 23and SPWM B at 24 to provide a signal to high side and low side powerswitch drivers. Through high speed, high power switching devices theinverter will generate high frequency power signal with a stabile 60 Hzfundamental sinusoidal frequency.

FIGS. 6 and 7 DC to AC Conversion DC to AC Conversion Occurs in 2Stages.

First stage in FIG. 6 is a DC to DC converter and the second stage is aDC to AC inverter. The battery voltage 50 is stepped up throughpush-pull topology of the DC/DC converter. At 62,63,64,65 high currentpower switching devices are employed to drive high frequency powertransformers at 60 and 61. In order to minimize resistive losses due tohigh incoming current, the step up process is split into two parts. T3at 60 and T6 at 61 are 2 identical high frequency transformers whichconvert the low battery DC voltage at 50 into high AC square wavevoltage at 51 and 49. This voltage is further rectified through thediode bridge 52 and filtered by C2 at 53 and C8 at 54 to obtain +Bus and−Bus voltage in reference to 0 Bus at 66. To obtain constant busvoltages, the duty ratio of power switching devices is controlled by U4at 55 which is a voltage controlled pulse width modulator. The switchingfrequency of DC/DC converter is set to approx. 40 kHz. Using about 40kHz switching frequency in DC/DC conversion, the size of transformersand switching losses are reduced.

Battery Charger

Battery charger 56 is a 24V Sealed Lead-Acid Battery Charger. It isconfigured as dual step constant current charger to provide a constantcurrent of approximately 4 amperes at variable battery voltage. Thebattery charger is short circuit protected. Once the battery voltagereaches certain voltage level, the charger switches to trickle chargecurrent to maximize and maintain highest possible battery capacity. Thepower supply for the battery charger 57 is a 150W switch mode powersupply which is powered by utility 120Vac 59. It is adjusted to providea constant voltage level of 30 volts.

Diode D2 at 58 is connected in parallel with the battery to prevent thedamage to pump control system in the case of reversing the batterypolarity.

FIG. 7

In DC to AC inverter stage once the +Bus 53 and −Bus 54 voltage has beenestablished, the +Bus and −Bus high DC voltage is further modified bymultiplicity of paralleled power switching devices at 70 and 71, whichare connected in half bridge configuration. The power switches at 77 and78 are driven by isolated high side driver at 79 and low side drivers at80. These drivers are controlled by SPWM A 81 and SPWM B 82 signals.Through this DC modification we obtain a high frequency SPWM powersignal at 83 with 60 Hz sine wave fundamental frequency. This signal isfiltered through inductor 72 and capacitor 73 configured as low passfilter to obtain 115V˜60 Hz voltage at 74 to drive sump pumps.

The half bridge configuration has the advantage over full bridgeconfiguration since it utilizes half as many power switching devices asneeded in full bridge configuration. Also by paralleling power switchingdevices the effective ON resistance reduces and minimizes the overallconduction losses. High speed power switching devices are employed toreduce switching losses. Diodes 75 and 76 are connected in parallel toswitching devices to protect them from back EMF from highly inductiveload.

FIG. 5

Inverted DC battery power from the inverter circuit at 74 FIG. 7 or theAC utility power at 59 FIG. 6 is distributed to pumps through RL3 at 32which is controlled by AC power detector logic at 26 FIG. 4. Relay 3 isa double pole double throw 12V relay. At 33 the current and voltage arebeing sensed for control purposes. The current sensing circuit at 34will provide the signal for overload condition and short circuitprotection of the inverter caused by locked pump impeller or shortcircuit on the inverter output. Voltage sensing circuit at 35 willprovide signal to the voltage controlled pulse width modulator at 55 inDC/DC converter stage in FIG. 6, to drive the power switching deviceswith variable duty ratio. This feedback loop will provide a constantBus+ and Bus− voltage at the output of the DC/DC converter stage.

Pump 1 at 40 is turned ON and OFF by RL1 at 36 which supplies power topump 1 through 38. Pump 2 at 41 is turned ON and OFF by RL2 at 37 whichsupplies power to pump 2 through 39. These relays are controlled byadvanced switching logic.

Switching Logic: This Section Details the Switching Logic of the ControlSystem in Each of the Three Possible Configurations: Parallel PumpConfiguration The Flowchart in FIG. 8 Represents the Pump Operation inParallel Configuration.

The advantage of this type of pump switching control over existing pumpcontrols is the presence of 2 AC pumps supplied with the nominal voltageand the 50% utilization on each pump. We employ 3 float switches whichalternate pump operation according to their status. This minimizes thepossibility of system failure due to stuck float switches, clogged pump,blocked pump or idling of the pump over long periods of time. Note thatthis same flowchart logic is applicable when the AC power failure occursand the system is running on DC backup power supply.

Normal Operation:

This flowchart starts at 100. At 101 both pumps are idling and awaitingthe float switch 1 or float switch 2 closure at 102. Notice that inparallel configuration both float switches from pump 1 and pump 2 areconnected in parallel and will turn ON either pump if any of these floatswitches are closed and turn OFF that pump only if both of them areopen. From the standpoint of implementation of this switching logiccircuitry this is necessary but also desirable feature to minimize therisk of pump failure due to bad or stuck float switches. As soon as oneof the float switches is closed at 102, pump 1 will cycle first at 103.A visual indication informs the user of pump operation at 104. Duringpump cycling the pump condition is monitored to sense if the pump isoperating normally. Overload at 105 will be triggered if the pump iseither stuck or drawing excessive current.

A third float switch is implemented and monitored to indicate themaximum liquid level in the sump hole. If the sump pump is not pumpingsufficient amount of liquid due to blockage of liquid, the maximum levelfloat switch at 106 is triggered and forces the system to alternatepumps. In normal case the primary or pump 1 will evacuate liquid belowboth pump 1 and pump 2 float switches at 107 and turn off the pump 1 at108. At 109 the float switches SW1 and SW2 are expecting next liquidinrush and both pumps will idle until one of the float switches closesand turn ON the alternative pump at 110. Note that in this scenario eachpump will act as backup pump for the other because they are assigned toperform exactly same tasks.

When pump 2 is cycling the system will provide visual indication at 111to inform the user of pump operation. The pump will be monitored foroverload condition at 112 and maximum liquid level by float switch SW3at 113. If system continues to function normally both pump floatswitches will open at 114 and bring the system back to initial startposition at 101.

Failure of Pump 1 Due to Overload or Due to Maximum Liquid Level:

Sump pumps are prone to failure because of continuous exposure tohumidity, deterioration from corrosion, and they are subject to foreignobject liquid blockage. Additionally, larger objects such as stonescould cause the impeller blockage and cause pump overload.

If pump 1 was cycling and failed due to overload at 105 or maximumliquid level at 106, the flowchart continues at 118 displaying the pump1 overload condition or check pump 1 indication due to maximum liquidlevel at 117. The system also turns ON the sound alarm to alert the userof abnormal pump operation.

At 119 pump 1 will be turned OFF and since the float switches arealready activated at 120, pump 2 will take over the cycling operationimmediately and evacuate remaining liquid from the sump hole at 121. Theuser is visually informed of pump activity at 122. The system checks foroverload condition at 123 or maximum liquid level at 124-125. As long asneither of the float switches is activated at 127 the system keepscycling pump 2 at 121. Only when both float switches are deactivated thesystem will turn OFF pump 2 and bring pump 2 back into a stand-byposition at 119.

Note that due to overload condition at 105 or maximum allowable liquidlevel condition at 106, pump 1 is permanently disabled and will not beemployed in further system operation. Pump 2 remains the only workingpump and the user is alerted and given the opportunity to take action tobring pump 1 back to normal operation. Furthermore if pump 2 is allowedto cycle and due to failure causes an overload at 123, the system willcome to a stop, indicate visually and audibly the failure condition at128, and idle in OFF mode at 115 until main reset switch is depressed at116. The main reset switch will reset all warning indicators and shouldbe used only if the pump problems are resolved. However if pump 2 allowsthe liquid to rise to maximum allowable level at 124, the system willNOT interrupt pump 2 operation, even if failure due to pump blockage issuspected, but rather allow it to further pump the liquid since pump 2is the only working pump. User will be alerted with audio and visualindicators at 126.

Failure of Pump 2 Due to Overload or Due to Maximum Liquid Level:

As in previous case of pump 1 failure due to overload or due to maximumliquid level this part of the chart will follow the same exact logic forpump 2 as for pump 1.

If pump 2 was cycling and failed due to overload at 112 or maximumliquid level at 113, the flowchart continues at 129 displaying the pump2 overload condition or check pump 2 indication due to maximum liquidlevel at 130. The system also turns ON the sound and visual alarm toalert the user of abnormal pump operation.

At 131 pump 2 will be turned OFF and since the float switches arealready activated at 132, pump 1 will take over the cycling operationimmediately and evacuate remaining liquid from the sump hole at 133. Theuser is visually informed of pump 1 activity at 134. The system checksfor overload condition at 135 or maximum liquid level at 136-137. Aslong as neither of the float switches are activated at 139, the systemkeeps cycling pump 1 at 133. Only when both float switches arede-activated system will turn OFF pump 1 and bring pump 1 back into astand-by position at 131.

Note that due to overload condition at 112 or maximum allowable liquidlevel condition at 113, pump 2 is permanently disabled and will not beemployed in further system operation. Pump 1 remains the only workingpump and the user is alerted and given the opportunity to take action tobring pump 2 back to normal operation. Furthermore if pump 1 is allowedto cycle and due to failure cause an overload at 135, the system willcome to a stop, indicate visually and audibly the failure condition at140, and idle in OFF mode at 115 until main reset switch is depressed at116. The main reset switch will reset all warning indicators and shouldbe used only if the pump problems are resolved. However if pump 1 allowsthe liquid to rise to maximum allowable level at 136, the system willNOT interrupt pump 1 operation even if failure due to pump blockage issuspected, but rather allow it to further pump the liquid since pump 1is the only working pump. User will be alerted with audio and visualindicators at 138.

Staggered Pump Configuration Characteristics of Staggered Configurationand Switching Logic:

Many sump wells are not wide enough to fit two pumps next to each other.In this situation staggered pump configuration is preferred. Instaggered configuration primary pump has a duty cycle of 80% andsecondary or backup pump a duty cycle of 20%. This way backup pump willbe less exposed to possible failure.

Staggered configuration employs 3 float switches which alternate pumpoperation according to pump status. Backup or secondary pump floatswitch acts as backup float switch for pump 1. Float switch 3, whichindicates maximum allowable liquid level, act as backup float switch forpump 2 and also for pump 1. This way primary pump 1 is well protectedagainst float switch failure.

This switching logic minimizes the possibility of system failure due tostuck float switches, clogged pump, blocked pump, or idling of the pumpover a long period of time.

It is important to note that in the case of AC power failure the pump 1cycle counter will be disabled to eliminate liquid elevation due to pumpchecking procedure.

The flowcharts in FIGS. 9 and 10 represents the pump operation instaggered configuration.

Normal Operation:

This flowchart starts at 200. At 201 a counter that counts pump 1 cycleis initiated. Both pumps are idling at 202 and awaiting pump 1 floatswitch closure at 203. When pump 1 float switch is activated, pump 1turns ON at 204. A visual indication informs the user of pump 1operation at 205. At 206 pump 1 is continuously monitored for overloadcondition, and at 207 for maximum liquid level. Once the liquid isevacuated from the sump pump well pump 1 float switch opens and turnsOFF pump 1. This cycle repeats four times unless there is an AC powerfailure in which case the pump 1 cycle counter is disabled and theoperation continues through 209 where status of switch 1 is monitored.

If however the AC power is not interrupted and the counter continues tocount pump 1 cycles, when called upon duty 5^(th) time, the pump 1 isnot allowed to cycle even if pump 1 float switch is activated at 213.The liquid will be allowed to elevate to pump 2 float switch at 214 andturn ON pump 2 for testing purposes at 215. A visual indication informsthe user of pump 2 operation at 216. Pump 2 is continuously monitoredfor overload condition at 217 and maximum allowable liquid level at 218.If there is no failure the process continues monitoring the condition ofpump 2 float switch at 219. As long as this float switch is activatedthe pump 2 will continue to cycle. Once pump 2 float switch opens at219, liquid level is at pump 2 float switch level. In order to evacuatethe remaining liquid, the operation is turned over to pump 1 again at220 and allows the liquid to be evacuated from the sump hole. The useris visually informed of pump activity at 221. During pump 1 cycling,overload condition at 222 and maximum liquid level at 223 iscontinuously monitored. Note that for pump 1 the maximum liquid levelwill be the level of pump 2 float switch. Pump 1 will cycle as long aspump 1 float switch is activated at 224. A visual indication informs theuser of pump 1 operation at 221. When pump 1 float switch deactivates at224 the whole cycle starts again from beginning at 200.

Failure of Pump 1 Due to Overload or Due to Maximum Liquid Level.

If pump 1 was cycling and failed due to overload at 206 or maximumliquid level at 207 the flowchart continues at 226 displaying the pump 1overload condition or check pump 1 indication due to maximum liquidlevel at 225. The system also turns ON the sound and visual alarm toalert the user of abnormal pump operation.

At 227 pump 1 will be turned OFF. At this point the system waits forliquid level to rise to pump 2 float switch level at 228 to turn ON pump2 at 229.

The user is visually informed of pump activity at 230. The system checksfor overload condition at 233 or maximum liquid level at 231. As long aspump 2 float switch is activated the system keeps cycling pump 2 at 227.As soon as pump 2 float switch is deactivated, the system turns OFF pump2 and brings pump 2 back in stand by position at 227. At this pointliquid level remains at pump 2 float switch level.

Note that due to overload condition at 206 or maximum allowable liquidlevel condition at 207, pump 1 is permanently disabled and will not beemployed in further system operation. Pump 2 remains the only workingpump and the user is given the opportunity to take action and bring pump1 to normal operation. Furthermore if pump 2 is allowed to cycle and dueto failure causes an overload at 233, the system will come to a stop,indicate visually and audibly the failure condition of pump 2 at 259,and idle in OFF mode at 258 until main reset switch is depressed at 260.The main reset switch will reset all warning indicators and should beonly used if pump problems are resolved.

However if the pump 2 cycles and allows the liquid to rise to maximumallowable level at 231, the system will NOT interrupt pump 2 operationeven if failure due to pump blockage is suspected, but rather allow itto further pump the liquid since pump 2 is the only working pump. Userwill be alerted with audio and visual indicators at 232.

Note that same flowchart will also hold for overload condition of pump 1at 222 and maximum allowable liquid level condition at 223.

Failure of Pump 2 Due to Overload:

Pump 2 cycles only periodically for testing purposes. If during cyclingpump 2 exhibits overload condition at 217, the operation continues at235 alarming the user visually and audibly of abnormal pump operation.

At 237 pump 2 will be turned OFF. Since both float switches are alreadyactivated, pump 1 will take over the cycling operation immediately andevacuate remaining liquid from the sump hole at 237. The user isvisually informed of pump activity at 238. The system checks foroverload condition at 239. When pump 2 fails both pump 1 and pump 2float switches are activated and the cycling of pump 1 will continueuntil liquid is evacuated from sump hole and pump 1 float switch isdeactivated at 243. At this point pump 2 float switch acts as sensor formaximum liquid level of pump 1 at 241. The system monitors the status ofpump 1 float switch at 245, idles at 244, and turns pump 1 ON at 237 ifpump 1 float switch is activated at 245.

Note that due to overload condition at 217, pump 2 is permanentlydisabled and will not be employed in further system operation. Pump 1remains the only working pump and the user is given the opportunity totake action and bring pump 2 to normal operation. Furthermore if pump 1is allowed to cycle and due to failure causes an overload at 239, thesystem will come to a stop, indicate visually and audibly the failurecondition at 257, and idle in OFF mode at 258 until main reset switch isdepressed at 260. The main reset switch will reset all warningindicators and should only be used if the pump problems are resolved.

However if the pump 1 allows the liquid to rise to maximum allowablelevel at 241, the system will NOT interrupt pump 1 operation even iffailure due to pump blockage is suspected, but rather allow it tofurther pump the liquid since pump 1 is the only working pump. User willbe alerted with audio and visual indicators at 242.

Failure of Pump 2 Due to Maximum Liquid Level:

Pump 2 cycles only periodically for testing purposes. If during thiscycling pump 2 exhibits maximum liquid level condition at 218, theflowchart continues at 236 alarming the user visually and audibly ofabnormal pump operation.

At 246 pump 2 will be turned OFF and since the both float switches arealready activated, pump 1 will take over the cycling operationimmediately and evacuate remaining liquid from the sump hole at 246. Theuser is visually informed of pump activity at 247. The system checks foroverload condition at 248. The cycling of pump 1 will continue untilliquid is evacuated from the pump hole and pump 1 float switchdeactivates at 254. At this point pump 2 float switch at 253 as well asmaximum liquid level float switch 3 at 250 act as sensor for maximumliquid level of pump 1. The system monitors the status of pump 1 floatswitch at 256, idles at 255, and turns pump 1 ON at 246 if pump 1 floatswitch is activated at 256.

Note that due to maximum liquid level condition at 217, pump 2 ispermanently disabled and will not be employed in further systemoperation. Pump 1 remains the only working pump and the user is giventhe opportunity to take action and bring pump 2 in normal operation.Furthermore if pump 1 is allowed to cycle and due to failure causes anoverload at 248, the system will come to a stop, indicate visually andaudibly the failure condition at 257, and idle in OFF mode at 258 untilmain reset switch is depressed at 260. The main reset switch should beonly used if the pump problems are resolved. However, if the pump 1allows the liquid to rise to pump 2 float switch that represents maximumallowable level for pump 1 at 253, the system will NOT interrupt pump 1operation even if failure due to pump blockage is suspected, but ratherallow pump 1 to further pump the liquid since pump 1 is the only workingpump. User will be alerted with audio and visual indicators at 251.

In both instances of parallel and staggered switching logic, there aremany variation of switching sequences of all three float switches infailure conditions. These failure variations are not included in theflowchart, however the system provides maximum security against pump andfloat switch failure in any switching scenario.

Single Pump Configuration

The flowchart in FIG. 11 represents single pump configuration

The optimal use of this system is not to be used with single pump, butit is able to run in single pump mode if one of the paralleled orstaggered pumps failed and is missing. This mode is implemented as a subcircuit of a staggered circuit.

The flowchart starts at 300 with idling pump at 301. Pump 1 float switchis monitored and when activated, pump 1 turns ON at 303. A visualindication informs the user of pump 1 operation at 304. Pump 1 continuescycling until the float switch opens at 309.

Pump 1 is monitored for overload and maximum liquid level condition. Ifpump allows the liquid to rise to maximum allowable level at 306, thesystem will NOT interrupt pump operation, even if failure due to pumpblockage is suspected, but rather allow it to further pump the liquidsince this is the only pump. User will be alerted with audio and visualindicators at 307.

Furthermore if pump 1 is cycling and due to failure causes an overloadat 305, the system will come to a stop, indicate visually and audiblythe failure condition at 308, and idle in OFF mode at 310 until mainreset switch is depressed at 311. The main reset switch will reset allwarning indicators and should be only used if the pump problems areresolved.

1. A method of operating one AC pump or plurality of AC pumps fromeither utility AC power or inverted battery DC power in case of AC powerloss. This method is comprised of continuous monitoring of power andpump mechanical condition, automatic triggering of controlled responseswith audible and visual alerts of operating status, controllingplurality of AC pumps from the same power source, and battery chargingcircuitry.
 2. The system of claim 1, operating a single pump FIG. 1 3.The system of claim 1, operating two pumps in parallel configurationFIG. 2
 4. The system of claim 1, operating two pumps in staggeredconfiguration FIG. 3
 5. The system of claim 1, wherein pumps can bemounted in different configurations comprising of single, parallel, andstaggered configurations.
 6. The system of claim 1, wherein parallelpump configuration switching logic is presented in FIG. 8
 7. The systemof claim 1, wherein staggered pump configuration switching logic ispresented in FIG. 9 and FIG. 10
 8. The system of claim 1, wherein singlepump configuration switching logic is presented in FIG. 11
 9. The systemof claim 1, wherein pumps are monitored for excessive currentconsumption in both cases when utility power is available and wheninverter is operating.
 10. The system of claim 1, wherein pumps aremonitored for reduced liquid pumping volume in both cases when utilitypower is available and when inverter is operating.
 11. The system ofclaim 1, wherein pump operation is alternated to reduce risk of failure12. The system of claim 1, wherein pump operation is alternated to avoidflooding due to single pump failure
 13. The system of claim 1, whereinpumps are alternated in certain sequence depending on theirconfiguration. The switching sequence is optimized for saidconfiguration.
 14. The system of claim 1, wherein liquid level sensingdevices are utilized to provide the optimum pump alternating operation.15. The system of claim 1, wherein the AC utility power will driveeither primary or backup sump pump.
 16. The system of claim 1, whereinthe inverter output will drive either primary or backup sump pump. 17.The system of claim 1, wherein during inverter operation the batteryvoltage level will drop and the output AC voltage of the inverter iskept at approximately same level.
 18. The system of claim 1, wherein theoutput of the inverter is alternating current.
 19. The system of claim1, wherein the inverter output is power signal of about 115Vrms andfrequency of about 60 Hz
 20. The system of claim 1, wherein the chargingmeans provides power to the battery at variable battery voltage andconstant current to maintain maximum battery capacity without damagingthe batteries by overcharging them.
 21. The system of claim 1, whereinthe battery voltages are monitored and displayed
 22. The system of claim1, including visual battery charging indicator
 23. The system of claim1, including audio alarm of system malfunction.
 24. The system of claim1, wherein the enclosure can be table or wall mounted.
 25. The system ofclaim 1, wherein pump conditions are monitored and displayed
 26. Thesystem of claim 1, wherein available power is monitored and displayed27. The system of claim 1, wherein temperature of the system ismonitored and protected from overheating